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OracleHighAvailability&DisasterRecovery(cont’d)
Primary
Database
Standby
Database
SYNCorASYNCRedoShipping
UsingOracleNet
q OracleDataGuard
– Providesdataavailabilityandprotectioninasimple,fast,and
reliableonewayreplication
– FordatacenterDR
– DGisnotintendedtobeafullfeaturedreplicationsolution
– OracleGoldenGateistherecommendedsolutionforadvanced
replicationrequirementssuchasmultimasterreplication,granular
replicationofasubsetofadatabaseandmore
– CanbePhysicalorLogical
• Physicalstandbyisanexactblockforblockcopyofaprimary
database.UsesRedoApplyinwhichredodatareceivedfroma
primarydatabaseiscontinuouslyappliedtoaphysicalstandbyusing
databaserecoverymechanisms.
• Logicalstandbyisinitiallycreatedasanidenticalcopyoftheprimary
databasebutlatercanbealteredtohaveadifferentstructure.
Appliesinfofromarchived/redologsbytransformingthedatainthe
logfilesintoSQLstatementsandthenexecutingSQLstatementson
thelogicaldatabase.Canbeusedforqueriesandreportingatany
time.
– AdditionalcostforOraclelicenses